dt-bindings: pinctrl: mt8195: change pull up/down description

For supporting SI units in "bias-pull-down" & "bias-pull-up",
change pull up/down description
and add "mediatek,rsel_resistance_in_si_unit" description.
Signed-off-by: Zhiyong Tao <zhiyong.tao@mediatek.com>
Link: https://lore.kernel.org/r/20210924080632.28410-3-zhiyong.tao@mediatek.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/pinctrl/pinctrl-mt8195.yaml

@@ -49,6 +49,12 @@ properties:
     description: The interrupt outputs to sysirq.
     maxItems: 1
 
+  mediatek,rsel_resistance_in_si_unit:
+    type: boolean
+    description: |
+      Identifying i2c pins pull up/down type which is RSEL. It can support
+      RSEL define or si unit value(ohm) to set different resistance.
+
 #PIN CONFIGURATION NODES
 patternProperties:
   '-pins$':
@@ -82,9 +88,85 @@ patternProperties:
       drive-strength:
         enum: [2, 4, 6, 8, 10, 12, 14, 16]
 
-      bias-pull-down: true
+      bias-pull-down:
+        description: |
+          For pull down type is normal, it don't need add RSEL & R1R0 define
+          and resistance value.
+          For pull down type is PUPD/R0/R1 type, it can add R1R0 define to
+          set different resistance. It can support "MTK_PUPD_SET_R1R0_00" &
+          "MTK_PUPD_SET_R1R0_01" & "MTK_PUPD_SET_R1R0_10" & "MTK_PUPD_SET_R1R0_11"
+          define in mt8195.
+          For pull down type is RSEL, it can add RSEL define & resistance value(ohm)
+          to set different resistance by identifying property "mediatek,rsel_resistance_in_si_unit".
+          It can support "MTK_PULL_SET_RSEL_000" & "MTK_PULL_SET_RSEL_001"
+          & "MTK_PULL_SET_RSEL_010" & "MTK_PULL_SET_RSEL_011" & "MTK_PULL_SET_RSEL_100"
+          & "MTK_PULL_SET_RSEL_101" & "MTK_PULL_SET_RSEL_110" & "MTK_PULL_SET_RSEL_111"
+          define in mt8195. It can also support resistance value(ohm) "75000" & "5000" in mt8195.
+          oneOf:
+            - enum: [100, 101, 102, 103]
+            - description: mt8195 pull down PUPD/R0/R1 type define value.
+            - enum: [200, 201, 202, 203, 204, 205, 206, 207]
+            - description: mt8195 pull down RSEL type define value.
+            - enum: [75000, 5000]
+            - description: mt8195 pull down RSEL type si unit value(ohm).
+
+          An example of using RSEL define:
+          pincontroller {
+            i2c0_pin {
+              pinmux = <PINMUX_GPIO8__FUNC_SDA0>;
+              bias-pull-down = <MTK_PULL_SET_RSEL_001>;
+            };
+          };
+          An example of using si unit resistance value(ohm):
+          &pio {
+            mediatek,rsel_resistance_in_si_unit;
+          }
+          pincontroller {
+            i2c0_pin {
+              pinmux = <PINMUX_GPIO8__FUNC_SDA0>;
+              bias-pull-down = <75000>;
+            };
+          };
 
-      bias-pull-up: true
+      bias-pull-up:
+        description: |
+          For pull up type is normal, it don't need add RSEL & R1R0 define
+          and resistance value.
+          For pull up type is PUPD/R0/R1 type, it can add R1R0 define to
+          set different resistance. It can support "MTK_PUPD_SET_R1R0_00" &
+          "MTK_PUPD_SET_R1R0_01" & "MTK_PUPD_SET_R1R0_10" & "MTK_PUPD_SET_R1R0_11"
+          define in mt8195.
+          For pull up type is RSEL, it can add RSEL define & resistance value(ohm)
+          to set different resistance by identifying property "mediatek,rsel_resistance_in_si_unit".
+          It can support "MTK_PULL_SET_RSEL_000" & "MTK_PULL_SET_RSEL_001"
+          & "MTK_PULL_SET_RSEL_010" & "MTK_PULL_SET_RSEL_011" & "MTK_PULL_SET_RSEL_100"
+          & "MTK_PULL_SET_RSEL_101" & "MTK_PULL_SET_RSEL_110" & "MTK_PULL_SET_RSEL_111"
+          define in mt8195. It can also support resistance value(ohm)
+          "1000" & "1500" & "2000" & "3000" & "4000" & "5000" & "10000" & "75000" in mt8195.
+          oneOf:
+            - enum: [100, 101, 102, 103]
+            - description: mt8195 pull up PUPD/R0/R1 type define value.
+            - enum: [200, 201, 202, 203, 204, 205, 206, 207]
+            - description: mt8195 pull up RSEL type define value.
+            - enum: [1000, 1500, 2000, 3000, 4000, 5000, 10000, 75000]
+            - description: mt8195 pull up RSEL type si unit value(ohm).
+          An example of using RSEL define:
+          pincontroller {
+            i2c0_pin {
+              pinmux = <PINMUX_GPIO8__FUNC_SDA0>;
+              bias-pull-up = <MTK_PULL_SET_RSEL_001>;
+            };
+          };
+          An example of using si unit resistance value(ohm):
+          &pio {
+            mediatek,rsel_resistance_in_si_unit;
+          }
+          pincontroller {
+            i2c0_pin {
+              pinmux = <PINMUX_GPIO8__FUNC_SDA0>;
+              bias-pull-up = <1000>;
+            };
+          };
 
       bias-disable: true